After recompiling all my C++ code in "Release" mode using the 8.0 compiler for windows, my set of QA test cases now takes more than twice as long vs. Visual C++ 6 compiled code. A bit depressing! I realize the Intel compiler has lots of great optimizations, but surely a the default /O2 should better the creaky old MS compiler!
Where should I start looking for problems? The code is computational C++, with lots of floating point work, but mixed with lots of C++ method calls and template instantiation.
The compiler options passed to the Intel compiler would the default "Maximise Speed" ones from VC++.
Pentium IV , 2Ghz, Windows 2000.